Brachial plexus injuries may occur in association with or without recognised shoulder dystocia. Until recently many medico-legal experts argued that these injuries resulted from the negligent use of excessive or misdirected traction. These experts did not accept that the natural forces of labour could cause the injury.

In cases of recognised shoulder dystocia, modern obstetric practice has recognised the importance of correct maternal positioning and the need to avoid excessive or misdirected traction, also the importance of not applying a rotational force to the fetal head. Informed practice and the increased use of caesarean section has not reduced the number of brachial plexus injuries.

Judges in two recent trials found that the natural forces of labour were the cause of the injury and that the birth assistants had not caused the damage. This has important implications for medical note writing, teachers and risk managers, medico-legal experts and lawyers.